Database independent Migration of Objects into an Object-Relational Database

This paper reports on the CERN-based WISDOM project which is studying the serialisation and deserialisation of data to/from an object database (objectivity) and ORACLE 9i.Comment: 26 pages, 18 figures; CMS CERN Conference Report cr02_01

A comprehensive part model and graphical schema representation for object-oriented databases

Part-whole modeling plays an important role in the development of database schemata in data-intensive application domains such as manufacturing, design, computer graphics. text document processing, and so on. Object-oriented databases (OODBs) have been targeted for use in such areas. Thus, it is essential that OODBs incorporate a part relationship as one of their modeling primitives. In this dissertation, we present a comprehensive OODB part model which expands the boundaries of OODB part-whole modeling along three fronts. First, it identifies and codifies new semantics for the OODB part relationship. Second, it provides two novel realizations for part relationships and their associated modeling constructs in the context of OODB data models. Third. it, provides an extensive graphical notation for the development of OODB schemata. The heart of the part model is a part relationship that imposes part-whole interaction on the instances of an OODB. The part relationship is divided into four characteristic dimensions: (1) exclusive/shared. (2) cardinality/ordinality, (3) dependency. and (A) value propagation. The latter forms the basis for the definition of derived attributes in a part hierarchy. To demonstrate the viability of our part model, we present two novel realizations for it in the context of existing OODBs. The first realizes the part relationship as an object class and utilizes only a basic set of OODB constructs. The second realization, an implementation of which is described in this dissertation, uses the unique metaclass mechanism of the VODAK Model Language (VML). This implementation shows that our part model can be incorporated into an existing OODB without having to rewrite a substantial subsystem of the OODB, and it also shows that the VML metaclass facility can indeed support extensions in terms of new semantic relationships. To facilitate the creation of part-whole schemata, we introduce an extensive graphical notation for the part relationship and its associated constructs. This notation complements our more general OODB graphical schema representation which includes symbols for classes, attributes. methods. and a variety of relationships. OO-dini, a graphical schema editor that employs our notation and supports conversion of the graphical schema into textual formats, is also discussed

Compensation methods to support generic graph editing: A case study in automated verification of schema requirements for an advanced transaction model

Compensation plays an important role in advanced transaction models, cooperative work, and workflow systems. However, compensation operations are often simply written as a^−1 in transaction model literature. This notation ignores any operation parameters, results, and side effects. A schema designer intending to use an advanced transaction model is expected (required) to write correct method code. However, in the days of cut-and-paste, this is much easier said than done. In this paper, we demonstrate the feasibility of using an off-the-shelf theorem prover (also called a proof assistant) to perform automated verification of compensation requirements for an OODB schema. We report on the results of a case study in verification for a particular advanced transaction model that supports cooperative applications. The case study is based on an OODB schema that provides generic graph editing functionality for the creation, insertion, and manipulation of nodes and links

A DESIGN OF AN OBJECT-ORIENTED DATABASE FOR EFFECTIVE DATA MINING

This paper focuses on the design of an object-oriented database (OODB), through incorporation of object-oriented programming (OOP) concepts into existing relational databases. The proposed approach makes use of the OOP concepts namely, inheritance, encapsulation and polymorphism to design an OODB and perform classification in it respectively. Usually, database is a collection of tables with common fields. In this study, those common fields are grouped together to form a single generalized table. The newly created table resembles the base class in the inheritance hierarchy. Polymorphism allows different classes to have methods of the same name and structure, performing different operations based on the calling object. The polymorphism is specifically employed to achieve classification in a simple and effective manner while Encapsulation ensures the hiding of the data and behavior of an object behind a limited and well-described interface. In Java terms, the limited and well-described interface is the set of public methods and attributes. The use of these object oriented concepts for the design of OODB ensures that even complex queries can be answered more efficiently. Particularly, data mining task and classification can be achieved in an effective manner.Â

Object Oriented Database Management Systems-Concepts, Advantages, Limitations and Comparative Study with Relational Database Management Systems

Object Oriented Databases stores data in the form of objects. An Object is something uniquely identifiable which models a real world entity and has got state and behaviour. In Object Oriented based Databases capabilities of Object based paradigm for Programming and databases are combined due remove the limitations of Relational databases and on the demand of some advanced applications. In this paper, need of Object database, approaches for Object database implementation, requirements for database to an Object database, Perspectives of Object database, architecture approaches for Object databases, the achievements and weakness of Object Databases and comparison with relational database are discussed

Migrating relational data to an OODB: strategies and lessions from a molecular biology experience

Journal ArticleThe growing maturity of OODB technology is causing many enterprises to consider migrating relational databases to OODBs. While data remapping is relatively straightforward, greater challenges lie in economically and non-invasively adapting legacy application software. We report on a genetics laboratory database migration experiment, which was facilitated by both organization of the relational data in object-like form and a C++ framework designed to insulate application code from relational artifacts. To our surprise, the framework failed to encapsulate three subtle aspects of the relational implementation, thereby "contaminating" application code. We describe the underlying issues, and offer cautionary guidance to future migrators

Querying an Object-Oriented Database Using CPL

The Collection Programming Language is based on a complex value model of data and has successfully been used for querying transforming and integrating data from a wide variety of structured data sources - relational, ACeDB, and ASN.1 among others. However, since there is no notion of objects and classes in CPL, it cannot adequately model recursive types or inheritance, and hence cannot be used to query object-oriented databases (OODBs). By adding a reference type and four operations to CPL - dereference, method invocation, identity test and class type cast - it is possible to express a large class of interesting safe queries against OODBs. As an example of how the extended CPL can be used to query an OODB, we will describe how the extended language has been used as a query interface to Shore databases

Developing a hyper media interface as a navigational tool for an object oriented database management system, 1995

A common difficulty associated with any large scale information base is traversing the repository in a coherent and purposeful manner. The scope and diversity of the media therein tends to be more of a distraction rather than a source of information. This phenomena is particularly relevant in current hypertext or hypermedia systems and is often referred to as becoming "lost in hyperspace". A solution to this hyperspace problem involves modeling the hyper system after the structured links associated with a database schema. The database schema inherently defines the formations necessary for the two basic forms of navigation in a hyper base - structural and associative. In order to depict the semantic relationships between nodes and links in a hyper system a model that is both readable and logic-oriented is necessary. Such a model can be expressed through conceptual graph notation. This paper documents the design of a hyper-media interface as a navigational tool for an object oriented database management system called 02. The navigational paths through the database are represented as a conceptual graph model